An electronic content guide may organize content such as television programs into categories and subcategories. The categories and subcategories may be topical as well as time-based. As a result, the user can select a given time-based criteria and within that time-based criteria select topical subcategories....http://www.google.de/patents/US7685520?utm_source=gb-gplus-sharePatent US7685520 - Electronic programming guide with selectable categories
